The Anopheles gambiae complex is arguably the most important insect from a medical perspective; it is the primary vector of malaria in Africa, and hence the world. The goal of these projects is to understand the evolutionary genetics of the group; this includes understanding phylogenetic relationships of species as well as population dynamics within species. Of greatest importance so far is the indication that closely related species may be exchanging genetic material by hybridizing in nature, the phenomenon known as introgression. Much of the evidence comes from studies of the chromosomal inversions of the group, genetic variants know to be very important to the biology of these mosquitoes. The issue of phylogeny and introgression is intimately tied to the evolutionary history of the inversions. Determining the evolutionary history of the chromosomal inversions in the Anopheles gambiae complex is a major focus of this proposal. A second major focus is to confirm or reject the hypothesis that cryptic taxa (perhaps new species) exist within the single species An. gambiae. The methods for achieving these goals are a combination of modern molecular evolutionary genetics and phylogenetic based on DNA technology. Such fundamental information on the evolutionary history and ongoing population dynamics of these species will have implications for design of control strategies. Control of the mosquito vector remains the most promising methods of controlling malaria.